Projectile fuze safe and arming device

ABSTRACT

A PROJECTILE FUZE SAFE AND SHELL ARMING DEVICE INCLUDING A FIXED MEMBER, A WEIGHTED ROTOR MOVABLE RELATIVE TO SAID FIXED MEMBER FROM INACTIVE TO ACTIVE POSITIONS, AND RETARDING MEANS EXERTING A RESILIENT FORCE PROPORTIONAL TO THE DISPLACEMENT OF SAID ROTOR FROM INACTIVE POSITION. LOCKING MEANS IS PROVIDED TO MAINTAIN SAID ROTOR IN ACTIVE POSITION ONCE SAID POSITION IS REACHED.

Nov. 16, 1971 J. P. CARROLL PROJEGTILE FUZE SAFE AND ARMING DEVICE Filed May 26. 1969 United States Patent 3,620,164 PROJECTILE FUZE SAFE AND ARMING DEVICE Joseph P. Carroll, 164 Columbia Heights, Brooklyn, N.Y. 11201 Filed May 26, 1969, Ser. No. 827,736 Int. Cl. F42c /22, 15/24 U.S. Cl. 102-78 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates generally to the field of ordnance, and more particularly to an improved fuze arming device for maintaining ordnance shells in safe condition until after the same have been fired, following which inertia means rotates relative to the casing of the shell to remove a barrier preventing contact of a firing pin with a detonating device. Devices of the instant type are known in the art, and the invention lies in specific constructional details permitting improved economy in manufacture, as well as improved reliability in operation.

Prior art devices include a weight free to rotate about a pin, the weight having a disaligned opening therein which interrupts the conductive train between a firing pin and a detonating device. The offset position is maintained by detents or pins. In operation, the shell is spun by the rifling of the discharging gun, the detent is overcome, and the weight rotates to aligned or active position. During its rotation, the rotating mass is caused to operate a gear, the teeth of which drive a gear train causing alternate movement of a pallet assembly or verge, thus slowing movement of the rotor so that a period of approximately one second or less is required before the shell is fully armed. This construction, while widely used, suffers from a number of disadvantages, including criticality of pallet assembly, complication in manufacture, the necessity of a separate sub-assembly to lock the device in active condition, as well as the difficulty of assembly.

In addition, should the rotor be started on its way toward active position, accidentally or otherwise, and the inertia force interrupted, there is no mechanism for returning the rotor to inactive position, and it is even possible for the rotor to reach active position as a result of mere manual handling.

It is therefore among the objects of the present invention to provide an improved arming device of the class described, in which the above mentioned disadvantages have been substantially eliminated.

Yet another object of the invention lies in the provision of an improved arming device in which the need for a gear train escapement has been eliminated, with its corresponding disadvantages, without any sacrifice in safety.

Another object of the invention lies in the provision of an improved arming device in which the cost of fabrication will be of a much lower order than has been the case in corresponding prior art devices, thereby materially lowering the cost of manufacture of individual ordnance fuzes.

These objects, as well as other incidental ends and advantages, will more clearly appear in the progress of the following disclosure, and be pointed out in the appended claims.

3,620,164 Patented Nov. 16, 1971 In the drawings, to which reference will be made in the specification, similar reference characters have been employed to designate corresponding parts throughout the several views.

FIG. 1 is a schematic view in elevation of a first embodiment of the invention.

FIG. 2 is a transverse sectional view as seen from the plane 22 in FIG. 1.

FIG. 3 is a schematic sectional view of a second embodiment of the invention.

FIG. 4 is a schematic sectional view, similar to that seen in FIG. 3, but showing certain of the component parts in altered relative position.

FIG. 5 is a sectional view of the second embodiment as seen from the plane 55 in FIG. 4.

FIG. 6 is a schematic view of a third embodiment of the invention.

FIG. 7 is a schematic view of a fourth embodiment of the invention.

In accordance with the invention, the device, generally indicated by reference character 10, includes a casing element 11 bounded by an outer surface 12 and an inner surface 13. An inwardly bent portion 14 forms a projecting lip 15 extending inwardly from the surface 13. An opening 16 is angularly displaced therefrom, the purpose of which will become more clearly apparent hereinafter. A forward wall 17 and a rearward wall 18 (with respect to the principal axis of the fuze in which the device is installed) provide aligned openings 19 and 20, respectively, which support a shaft 21 for rotation, the shaft in turn supporting an eccentrically mounted rotor 22.

The rotor 22 includes a bore 23, the axis of which is parallel to that of the shaft 22 so as to be movable between an inactive position indicated by reference character 24 and an active position 25 in which the bore is aligned with a firing pin (not shown) which may project to or therethrough to activate a detonator (not shown) to allow firing of the shell. In this position, the bore 23 is aligned with openings 26 and 27 in the walls 17 and 18, respectively.

An arcuate cut out segment 28 extends over an arcuate displacement coextensive with the degree of permissable angular rotation. A detent 29 bears against a radial wall 30, which engages a fixed pin 31 when movement in the direction of the arrow 32 has been completed. A bore 33 communicates with a slot 34, and engages a first end 35 of a fiat spring 36. The second end 37 thereof extends outwardly to be positioned in the flat opening 16.

OPERATION Upon the loading of the fuze and firing of the projectile (not shown) in which the device is incorporated, as soon as minimum threshold is achieved, the detent 29 releases. Thereafter, inertial and centrifugal force acting upon the rotor causes it to rotate against the spring 35. Upon achieving a predetermined angular rotation, the stop pin 31 prevents further motion, and the spring 35, which has been continuously deforming, has reached a position where the second end 37 engages the projecting lip 15 to maintain the device in locked activated condition. If, for any reason, rotation should stop prior to the above position being reached, the spring causes the rotor to return to its initial position, the rotation of the rotor being sufficient to permit the detent 29 to again engage.

Turning now to the second embodiment of the invention, generally indicated by reference character 40, and illustrated in FIGS. 3 and 4 in the drawing, parts corresponding to those of the principal embodiment have been designated by similar reference characters with the additional prefix 1. This embodiment is basically similar to the first embodiment, but is so positioned as to be activated by linear acceleration of the shell, rather than rotational velocity. Thus, the axis of the shaft 121 is transverse with respect to the principal axis of the projectile, and the bore 123 rotates from a transverse position to a parallel position (compare FIG. 3 with FIG. 4) to activate the device.

In the third embodiment of the invention, generally indicated by reference character 45, parts corresponding to those of the principal embodiment have been designated by similar reference characters with the additional prefix 2. In this embodiment, the spring 35 of the first embodiment has been replaced by a compression spring 46, both ends of which are fixed.

In the fourth embodiment, shown in FIG. 7 in the drawing, parts corresponding to those of the principal embodiment have been designated by similar reference characters with the additional prefix 3. In this embodiment, the device, generally indicated by reference character 47 is provided with a tensile spring 48, both ends of which are fixed.

In all of the disclosed embodiments, owing to the presence of a spring, the resilient force of which is dependent upon the degree of displacement of the rotor from inactive position, provides means whereby if the acceleration imparted to the shell is not continued to a degree sufficient to impart adequate movement through inertia to the rotor, the rotor will return to its inactive position, thus insuring complete safety. In addition, this spring permits the elimination of prior art clockwork mechanism, which, owing to its complication, is both expensive and to a degree considerably less reliable in operation.

I wish it to be understood that I do not consider the invention limited to the precise details of structure shown and set forth in this specification, for obvious modifications will occur to those skilled in the art to which the invention pertains.

I claim:

1. An arming device for projectile fuzes comprising: a relatively fixed element adapted to be incorporated as part of a fuze, a shaft carried by said first element, a weighted rotor carried by said shaft for rotation with respect to said relatively fixed element between inactive and active positions; means for maintaining said rotor in inactive position in the absence of an inertial force sufiicient to release the same; and combination resilient means for retaining said rotor in active position and tending to retard movement of said rotor from said inactive position to said active position by exerting a continuously increasing retarding force proportional to the degree of displacement of said rotor from inactive position; said last mentioned means including an elongated spring fixed at a first end thereof to said rotor, and free at a second opposite end thereof and slidingly bear against said fixed member, such that rotation of said rotor progressively bends the same in a given direction at points medial to said first and second ends.

2. Structure in accordance with claim 1, in which said free end of said spring projects through an opening in said first element when said rotor is in inactive position to provide a means for visually determining that said device is in unarmed state, said free end, when said rotor is in active position engaging a lip formed on an inner surface of said first element to lock said rotor in active position.

3. Structure in accordance with claim 1, in which said rotor is mounted for rotation about an axis perpendicular to the principal axis of said rotatively fixed element, so as to be responsive to linear acceleration imparted to said fixed element.

References Cited UNITED STATES PATENTS 1,688,652 10/1928 Pearson l0279 2,362,987 11/1944 Church et a1 l0279 2,711,695 6/1955 Williams l0279 2,900,908 8/1959 Burrell l0279 X SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R. l0279 

